Credit: The Associated Press

San Salvador Mayor Norman Quijano, the candidate of the Nationalist Republican Alliance, known as ARENA, shakes hands with a supporter who is waiting in line to acquire his national identification card that will allow him to vote, in San Salvador, El Salvador, Friday, March 7, 2014. A former Marxist guerrilla who has promised to continue the government's popular social programs is poised to win El Salvador's presidential election runoff on Sunday, giving the ruling party, the Farabundo Marti National Liberation Front, or FMLN, a second consecutive term.

SAN SALVADOR, El Salvador — Authorities declared El Salvador's presidential runoff election too close to call late Sunday, with just a 0.2-percent margin separating a one-time Marxist guerrilla and the conservative former mayor of El Salvador's capital.